Imaging lenses (see, for example, Patent Document 1) used in small image capturing devices embedded in mobile terminals or the like are required to have high resolving power of about 1 to 2 μm on an imaging surface, due to development of image sensors with increased pixels. The imaging lenses are also required to have a shorter entire length due to ever increasing demand for thinner mobile terminals or the like. The high resolving power may be achieved by an imaging lens having an aspherical lens surface. Thus, almost all the lens surfaces of conventional imaging lenses used in small image capturing devices are aspherical. Another possible solution is to increase the number of lens to achieve the imaging lens with high resolving power. Logically, the increased number of lenses simply leads to a larger space required for the lenses to be inserted, and thus results in a longer length of the entire imaging lens.